In a ratcheting up of tensions between NATO and Russia, both are accusing the other of failing to uphold agreements signed between the two sides since the dissolution of the Soviet Union.

Following Russia's annexation of Crimea and the buildup of Russian troops on the border with Ukraine, NATO announced that it was suspending "all practical civilian and military cooperation" with Moscow. It also has stepped up military maneuvers, sending surveillance planes to Poland and U.S. fighter jets to the Baltic states, in member countries located on Russia's borders.

At a March 3 news conference in Moscow, Russian Foreign Minister Sergei Lavrov said the moves were in violation of the Founding Act agreement, signed in 1997. The accord stated that "in the current and foreseeable security environment" NATO would carry out collective defense by "reinforcement rather than by additional permanent stationing of substantial combat forces."

At a separate press conference, NATO Secretary-General Anders Fogh Rasmussen called Lavrov's comments "propaganda and disinformation," adding that the alliance's actions did not involve permanent stationing of combat forces.

"In the same document Russia pledged to respect territorial integrity, sovereignty, and political independence of other states, and refrain from the threat or use of force," he said. "And that's exactly what Russia is not doing."

Despite overwhelming evidence to the contrary (we covered this in detail here), Moscow recently denied violating Ukraine's territorial integrity, claiming that the new government in Kyiv, which claimed power after former President Viktor Yanukovych fled the capital, itself "pushed" Crimea away.

Judy Dempsey, a senior associate at Carnegie Europe, tells RFE/RL that technically NATO is not breaking the rules of the agreement.

"There are no soldiers wearing NATO uniforms or NATO emblems stationed in any of the Eastern or Central European countries of the Baltics," she says. And the military exercises are "not permanent."

Nonetheless, she says Moscow's resentment of NATO is genuine and there is a sense that with the military partnership drawing down its forces in Afghanistan at the end of 2014, it is "going home" and returning to a mission whose chief focus is the collective defense of Europe.

In this light, and with NATO states on Russia's borders seeking an even greater role for the alliance following Russia's incursion into Ukraine, "anything NATO does is going to be interpreted [by Russia] as aggressive or undermining or provocative," she says.

Moscow, for its part, appears to have been engaged in a piecemeal effort to form a legal rationale for its efforts in Crimea -- particularly since UN members overwhelmingly rejected its annexation of Crimea in a late March vote.

Russia had argued that the Crimean vote to join with Russia, which was carried out under the watch of Russian soldiers and pro-Russian forces, was legal under the principle of self-determination.